This grey sky above Duluth is the calm before the storm.Another big snow storm and potential blizzard is coming Thursday night into Saturday morning.

"Beginning late Thursday night, if you've got travel plans I'd cancel them or leave Thursday or Saturday. All day Friday, things will be heavy, lasting through Saturday morning."

This is the time of year we usually start worrying about warm weather storms but the cold ones pack a punch, too.

"Winter storms are just as dangerous the summer variety, 'though they tend to last longer and you do have more time to prepare."

The approaching storm could whip up snow totals similar to the ones that hit the Iron Range earlier this week.

The prime target this time will be the Twin Ports region.Carol Christenson of the Weather Service says it's time to prepare now for up to a three-day storm.

"That would mean food, water, milk, non-perishable items, medicines, baby items because you may not be able to get out for a few days."

Once things settle down Saturday afternoon, more spring-like conditions should return and that could bring trouble of a different flavor.

"It's spring in the Northland and that means roller coaster weather. By Sunday, we're talking 40's and maybe even 50's and 60's by the start of next week which will mean rapid melting and the fear of flooding."